Interventional medicine is the collection of medical procedures in which access to the site of treatment is made through one of the patient's blood vessels, body cavities or lumens. For example, angioplasty of a coronary artery is most often performed using a catheter which enters the patient's arterial system through a puncture of the femoral artery in the groin area. The procedure is referred to as PTCA, or Percutaneous (through the skin), Transluminal (through the blood vessel), Coronary (in the vessel of the heart), Angioplasty. Other interventional medical procedures include assessment and treatment of tissues on the inner surfaces of the heart (endocardial surfaces) accessed via peripheral veins or arteries, treatment of vascular defects such as cerebral aneurysms, removal of embolic clots and debris from vessels, treatment of tumors via vascular access, endoscopy of the intestinal tract, etc.
Interventional medicine technologies have been applied to manipulation of instruments which contact tissues during surgical procedures, making these procedures more precise, repeatable and less dependent of the device manipulation skills of the physician. Some presently available interventional medical systems for directing and manipulating the distal tip of a medical device by actuation of the distal portion of the device use computer assisted navigation and an imaging system for providing imaging of the device and blood vessels and tissues. Such systems can control the navigation of a medical device, such as a catheter, to a target destination in an operating region using a computer to orient and guide the distal tip through blood vessels and tissue. In some cases, when the computed direction for reaching the target destination is determined and the medical device is extended, the device tip may not reach the intended target exactly due to inaccuracies in the device or deviations in physical or geometric characteristics of the device from its ideal properties. A steering correction may be required to properly reorient the device to reach the intended target. To reach the target destination, a navigation system must accurately orient the device tip as it approaches the target before advancing the remaining distance to reach the given target. A method is therefore desired for controlling movement of a medical device approaching the target destination that will verify the device tip is being accurately guided to the intended destination before advancement, and will allow for accurate navigation in real time.